# Mathematics 221

This is the homepage for Section 61 (MWF 12:00 in Tech M152), taught by Gui-Qiang Chen, Prof. of Math. Winter Quarter 2002

Office: Lunt 306

Office Hours: Mondays, Wednesdays 3:05-3:50 pm or by appointment

Teaching Assistants: Dianwen Zhu, Lunt B14; Office Hours: Mondays 2-4, Wednesdays 2-3; Email: zhudw@math.nnorthwestern.edu; Phone: 467-1956.
Todd Fisher, Lunt B13; Office Hours: Mondays and Wednesdays 2-3, Thursdays 1-2; Email: tfisher@math.northwestern.edu; Phone: 467-1958.

Text Book: Elementary Differential Equations (7th Ed.) W. Boyce and R. DiPrima

Quiz Sections: Students with last initial A-L meet with Dianwen Zhu in Lunt 102.
Students with last initial M-Z meet with Todd Fisher in TCH LG 72.

I will use a 90% - 80% - 70% - 60% scale to determine A--B--C--D grades:
Final Exam 30%,
Hour Exams 20% each,
Homework quizzes 30%.

Exams: Two midterms and final.
To be excused from an exam, except for sudden illness, you must make arrangement at least 24 hours before the exam is scheduled. Anyone missing an exam without previously arranging to do so will receive 0%. I do not give make-up exams.

Dates (Subject to change, except for final):
1st Hour Exam: Wed., Feb. 6, 2002
2nd Hour Exam: Wed, Feb. 27, 2002
Final: Tuesday, March 19, 2002

Webpage: Please check my webpage for B21 at
http://www.math.northwestern.edu/~gqchen/teach/B21/math221-winter2002.html
for update information.

## Maple worksheets

Here is the information on Maple worksheets. You may try the demonstration worksheet.

Then do the following worksheets as these topics are discussed in class.

WS1
, on Slope Fields.

WS2
, on Numerical Solutions.

WS3
, on Forced Oscillations.

WS4
, on Linear Systems of Differential Equations.

WS5
, on Series Solutions for Variable Coefficient Equations.

## Homework

(Note that the following schedule is only approximate. Often a particular topic will spill over into a subsequent lecture.)

1/7 Read Sections 1.1-1.4. Do problems 1.1: 1, 3, 7;
1.2: 1b, 2b, 7;
1.3: 1, 4, 5, 7, 18, 20

1/9 Read Sections 2.1, 2.3. Do problems 2.1: 7, 13, 18;
2.3: 1,2,18

1/11 Read Sections 2.2. Do problems 2, 15, 19, 21,22,29

1/14 Read Section 2.4, 2.5. Do problems 2.4: 6, 13, 14,15,17

1/15 Discussion Section

1/16 Read Section 2.6. Do problems 4, 11, 16, 20, 27

1/18 Read Sections 3.1, 3.2. Do problems 3.1: 6, 9, 16, 21, 22;
3.2: 5, 11, 13, 14, 17

1/21 Read Section 3.3. Do problems 4, 6, 10, 16, 20, 23

1/22 Discussion Section

1/23 Read Section 3.4. Do problems 4, 9, 12, 20, 21, 32, 25, 29

1/25 Read Section 3.5. Do problems 5, 13, 20, 25, 30, 15

1/28 Read Section 4.2. Do problems 1, 8, 11, 15, 18, 29, 32, 37

1/29 Discussion Section

1/30 Read Section 3.6. Do problems 5, 8, 11, 14, 18, 22, 25

2/1 Read Section 3.7. Do problems 4, 5, 8, 11, 14, 17, 18, 21, 22, 23, 28, 30

2/4 Review

2/5 Discussion Section

2/6 Hour Exam

2/8 Read Sections 5.1, 5.2. Do problems 5.1: 10, 13, 18, 20, 21, 24, 27;
5.2: 3, 5, 8, 16, 19, 20, 21

2/11 Read Section 5.3. Do problems 3, 4, 6, 7, 10, 11, 15, 18, 22, 23, 24

2/12 Discussion Section

2/13 Read Section 5.4, 5.5. Do problems 5.4: 5, 6, 13, 15, 17, 19, 20, 21, 24, 26;
5.5: 13, 15, 19, 21, 23, 28

2/15 Read Sections 7.1-7.3. Do problems 7.1: 5, 7, 8, 12, 14;
7.2: 4, 8, 11, 15, 19
7.3: 5,6,10,11,14,15

2/18 Read Section 7.4. Do problems 1, 2, 4, 5, 6, 8, 9

2/19 Discussion Section

2/20 Read Section 7.5. Do problems 3, 5, 8, 10, 14, 16, 19, 23, 28, 29

2/22 Read Section 7.6. Do problems 8, 9, 10, 11, 15, 20, 21, 27

2/25 TBA

2/26 Discussion Section

2/27 Hour Exam

3/1 Read Section 7.8. Do problems 5, 7, 10, 11, 15,17,18

3/4 Read Section 8.1. Do problems 1, 3, 5, 7

3/5 Discussion Section

3/6 Read Sections 8.2, 8.3. Do problems 8.2: 1, 3, 5, 7
8.3: 1, 3, 5, 7, 9, 11, 15, 18, 20

3/8 TBA

3/11 Review

3/12 Discussion Section (Review)

3/19 Final Exam 12-2pm ( Tuesday!!)

Here are some old final exams old exams